Fission‐track dating of lower Palaeozoic sandstones at Tatong, North Central Victoria

Abstract

Fission‐track dating has been applied for the first time to detrital mineral grains in sedimentary rocks. Unfossiliferous sandstones associated with Cambrian greenstones near Tatong, Victoria contain detrital zircon grains with an average age of 427 ± 20 m.y. This date provides a maximum age for the sandstones, so that they are younger than the Cambrian rocks, and have been tectonically juxtaposed. Radiometric dates for the eastern highlands of Victoria range from 390 to 460 m.y., and this mixed granitic‐metamorphic terrain may be the source for the zircons dated.